Cutting die mounting and ejector



June 30, 1953 J. E. MccLELLAN CUTTING DIE MOUNTING AND EJECTOR FiledJupe 1o. 1948 nnnnnnn u [EN Patented June 30, 1953 UNITED STATESCUTTING'DIE MOUNTINGAND EJECTGR Joseph E. McClellan, Oakland, Calif.,assigner to` himself and La Verne S. McClellan, Oakland, Calif., asjoint tenants Application June 10, 1948, Serial No. 32,097

The invention relates to a die for cutting blank pieces from leather andother homogeneous brous sheet materials. i

The primary object of' the invention is to provide a die set which isoperative to effective a clean cutting of fibrcussheet-material, andparticularly leather.

Another object ofthe invention is to provide a` blanking die set ofthecharacter described in which a sheet to be cut is positivelyl grippedbefore and while the cutting element is applied.

A further Objectis toprovide a die-set of the character described whichis particularly adapted for its mounting in, and actuation by, astamping machine having a power-controlled plunger which isreciprocativewith respect to a bolster o1' bed of the machine.

' The invention possesses other objects and features of advantage, someof which, with the foregoing, will be set forth' or be apparent in thefollowing description thereof, and in theaccompanying drawings, inwhich,

Figure l is a side elevation of a machine mounting the die set, lthevdiiferent` die assemblies being mutually separated to their limit.

- Figure 2 is a plan. view of the die setV taken at the line 2 -2 inFigure 1', portions of the structure being broken away.

Figure 3 is a vertical section of the die set taken at a plane throughtheline 3 3 of Figure 2, the co-operating die assemblies being separatedasin'Figure 1.

Figure 4 is an enlarged portion oflthe showing of' Figure 3 Vadjacentand across a cutting line of the die set.

Figures 5 and 6 show the die assembly sections of Figures-3 and 4respectively, but witha presser foot device of the male die clamping awork piece against the opposed face of the die block of the female diebefore cutting of a blankl is effected.

Figures 7 and 8 respectively show the die assembliesiof Figures 3 and 4asrelated lat the end of a working stroke ofthe male die.

By reason of itsv inherent structure, leather is recognized as one ofthe most difficult of sheet materials from which to cut blanks,particularly if the leather isl ofY the desired thickness and qualityfor such elements as glove and shoe-upper parts. Because thehomogeneously brousfna.-

ture of leather has heretofore made its die cuti ting mechanicallydilicult and vuncertain with; available dies, the practice of cuttingblanks of leatherv by striking a hand-positioned cutting die havingitscutting edge supporting the die upon 2 Claims. (Cl. 164-33) v 2 asheet of leather. placed on a lead or woolen anvil face is still largelyfollowed, even though the methodis extremely wasteful of timebecause thecut-out blanksl frequently require hand trimming, and relativelyfrequent sharpening or replacements of the cutting element and/or theprovision ofa new.v anvil face are required. The present die sethasbeen` sov designedv as to. eliminate the labor and mechanicaldifliculties of the aforesaid usuali practice, While providing for amachine operation of thevcooperative dies of a set inav speedy andeffective mannery for. cutting out blanks from ash'eet of leather, orsome other material of -a similar nature.

For purposes of illustration, a die set embodying the featuresof myAinvention is shown as operatively associated' with a hydraulicallyoperated blanking press H having ayC-shaped frame l2 providing a clearWorking space between its: upper and lower arms I3 and'A I4respectively. At its forward extremity, the upper frame arm I3 mounts ahydraulic cylinder I5; inY which a dou-- ble-acting pistonv 2li isoperative with its piston rod I6 extending into the working. space ofthe frame to variable degrees in accordance with the position of itspiston in the cylinder. l5, the extending rod portion carryinga cuttingdiev assembly l-l. The lower arm I4- of the frame:` l2 provides abed-plate or bolster I9 on which.Y the other die assembly |8- of the dieset issupported in cooperative relationto the upper die assembly I1which is suitably held against rotation about the piston axis, or anyother upright axis.

As particularly shown, the lower endz of the piston rod I6 is reduced toprovide a portion i6 extending from a shoulder IG and terminating in areduced threaded portion 16". A plate member 2| receives the piston rod.portion I6' therethrough and is arranged to constantly engagel the rodshoulder IS", said. member comprising an element of a male die assemblywhich primarily comprises a cutter 22 carried by a block 23 which. is inturn xed to. and beneath the platein unitary association therewith; themember 23'. has an interioropening receiving the piston rod portion l5therethrough, and is unitarily secured tothe plate-2| by an appropriatenumber of screws 2@ threadedly engaging the plate, whereby it andtheplate 2| comprise a base member for the Working die parts. Thecutting blade 22v extends peripherally around the block 2?, isVrelatively thin and of uniform thickness, is suitably xed to the block:edge as'byscrews 225, andis continuous or-effectively so, wherebyitsdownwardly extending sharpenedcuttingv edge 22 defines a continuouspredetermined line of cutting for the die in accordance with theperipheral outline of the block which is that of a blank to be cut.

It will now be noted that the fixed lower die assembly I8 essentiallyprovides a continuous groove 26 which is arranged to complementarily andclosely receive in its upper portion the cutting edge portion 22 of thecutting blade 22 when the upper die assembly I1 is in its fully loweredposition. For providing the groove 26,

the present lower die assembly |6 comprises a base plate 21 mounting aninner die block member 28 having its periphery defining the inner wallof the groove 26, and an outer die block member 26 encircling the member28 and having its bore dening the outer wall of the groove 26. The upperfaces of the members 21 and 28 are flat and mutually coplanar andcooperatively provide the support face for a work-piece sheet L ofleather, or other sheet material to be cut. Preferably, and as shown,the sharpened edge 22' of the cutting blade 22 is bevelled inwardlytherearound, and the right-angle edge 29' provided at the top of thebore of the outer die block member 29 comprises and is utilized as ashearing edge in cooperation with the cutting edge 22 of the blade.Bolts 3| extending upwardly through the base member 21 into the members28 and 29 fix the latter members to the base to provide the groove 26.

To facilitate an appropriate positioning of the inner block member 28for receiving the bolts 3| which secure it to the base plate 21, themutually opposed faces of the member and base may be complementarilystepped at their portions within the line of the bolts 3|. Also, agroove 21 may extend from the upper face of the base member 21 inregistration with the groove 26, the groove 21' providing a, receptaclefor small particles of the cut material which may descend through thegroove 26. The described lower die assembly I8 may have its base 21fixed to the bed plate I8 of the press in any suitable manner andfollowing its setting to register its groove 26 with the lowered cuttingblade 22 of the complementary die assembly |1 which is to coact with it.

Though a downward movement of the cutter 22 against a piece of materialL supported beneath it upon the positioned die plate 28-29 and into thegroove 26 is designed to effect a shearing cut through the materialbetween the edges 22' and 29' respectively of the cutter 22 and theouter die block 29, it has been found that a clean `cutting of fibrousand laterally stretchable material such as leather may not be assured bysuch an operation of the die set so far described. The aforesaiddifficulty has been overcome in the lpresent die set by providing ameans for clamping a, work piece L against the die plate 28-29, andadjacent the line of cut, before and while the cutter engages thematerial in cutting and return strokes thereof; the present work-holdingmeans comprises a presser-foot carried by the movable assembly |1 andappropriately cooperative with the xed assembly i8.

Noting that the cutting blade 22 extends appreciably below the block 23which mounts it and defines a blade-bounded space of uniform boreextending beyond the lower face of'said block as the line ofreciprocation of the assembly |1, a member 32 vis slidably mounted insaid bore and on the reduced piston rod portion I6' for a limitedreciprocative guided movement between a normal position in which itextends beyond the cutting edge 22 to a position in which the cuttingedge 22' extends beyond its lower face 32. The present member 32 isrecessed from below to provide a cavity 34 below its hole which receivesthe piston rod portion I6', and a nut 33 xedly mounted on the threadedend |6 of the rod |6 engages the inner end of the recess and functionssolely as a radial stop flange to limit a lowering of the member 32 withrespect to the overlying blade-carrying block 23.

The member 32 is normally held seated upon the top of the nut 33 by theaction of a suitable number of helical compression springs 35 interposedin a line thereof between the member and block; in the presentstructure, the springs 35 extend from seats upon the top of the member32 to the bottoms of downwardly-opening sockets 36 provided in the block23. The screws 24 which fix the block 23 on the base plate 2| extendfrom the bottoms of the sockets 36 whereby their heads provide thespring seats of the sockets. Noting that the end face 32 of the member32 is arranged to seat upon the work piece L while the cutter 22 isoperatively advanced beyond it, the cavity 34 is deep enough to permitthe limiting extension of the cutter beyond the member without engagingthe lower piston rod extremity or the nut 33 with the work piece; asparticularly shown, an upper portion 32" of the member 32 in alignmentwith the cavity 34 is offset upwardly to provide for the desiredconstant disposal of the piston rod end |6"' and the nut 33 thereonwithin the cavity. The portion 32" of the member 32 is arranged for itsfree disposal in a recess 23' extending into the blade-carrying block 23from its under side whenever the member 32 is displaced upwardly withrespect to the block 23; the arrangement is designed to provide amaximum clearance between the fully raised cutting die assembly |1 andthe fixed lower die I8, whereby to facilitate the appropriate manualpositioning of a work-piece for the operation of the die set against it.

A member 31 receives and is slidable on the cutting blade 22, and isarranged for substantially the same limited reciprocative movement withrespect to the blade as the member 32. Bolts 38 extend upwardly from themember 31 and slidably through holes 39 provided in the plate 2|, saidbolts having their heads 38 disposed above the plate 2| for supportingthe member 31 therefrom in limited spaced adjusted relation thereto. Aline of helical springs 4| encircles the bolts 38 and said springshaving their upper and lower ends respectively seated at the end face ofthe plate 2| and the bottoms ofseat sockets 42 extending into the member31 at the bolts 38, the arrangement being such that the member 31 isdisplaceable toward the plate 2| against the joint resistance of the setof springs 4|. It is to be noted that the threaded engagement of thebolts 38 in the member 31 permits an adjustment of this member withrespect to the corresponding inner member 32 when the members are intheir limiting extended positions with respect to the blade 22.

' It will now be noted that the lower faces 32 and 31 of the respectivemembers 32 and 31 are at and are arranged to be normally coplanar,whereby they'may simultaneously engage the upper vface of a sheet L atthe portion to be cut from it as a blank. Since sheets of leather andother materials to be cut may not be of absolutely uniform thickness, itis preferable that the under face of the member 32'be recessed frompositive gripping ofb a sheet-'L immediately adjacentthe cutting linewhen the member is projected' against the sheet. While the faces 32 and3'1"V engage the top of a work-piece sheet L, a lowering of theunitarycutter assembly I-'Iis'arranged to provide a shearing cut ofthematerial at the edge 29 of the-die block 29v by the cutting edge-22ofthe blade 22; if the material L is of leather or other homogenousiibrous material', the workingn application of the cutting blade must'berelativelyrapid. Noting that the membersaZ and 3i aredisposable toresiliently grip a sheet L between them andY the upper faces of the op.-posed die block members 28- and 291 respectively, it-will be understoodthat the members32zand- 3l function as mutually independent presser.feet within and without the blade 2'2, andi comprise independentlyyoperativesections of a presser foot assembly-SZ-'lv which enclosesand'is guidedon 'the cutting blade 22 fora working projection of-theblade beyond the faces 32 and 3l of the respective sections 32 and31 in working and return strokes while the latter sections. clamp awork-piece to the respective die blocks 28 and 29 as a work-holdingmeans.

While I have herein described the disclosed cutting die assembly Ihavingpresser feet. as being cooperative with the fixed` die block assemblyI3, it will be understood that this assembly may operate with reasonableefficiency against a worlrpiece placedY on a fixed lead or wooden anvilface in'lieu of a die block assembly such as that presently provided. Itwill also'be noted that either of the presser feet 32 or 3l may beprovided and utilizedalong, though their joint use will usually bepreferred in the cutting of leather andother relatively soft fibrousmaterials. Also, in an arrangement such as the present cutter dieassembly, the springs behind the presser feet 32' and 3l' assure apositive and progressively increasing pressure ofthe feet against awork-piece sheet L as. the cutting blade moves through andbeyond thesheet for its cutting of-a blank therefrom.

Referring now to the actuation of the piston rod I5 to effect working.and return strokes of the cutting die assembly il, means are preferablyprovided whereby successive cutting cycles may be provided in asemi-automatic manner. As generally indicated in Figure l, the operatingfluid for the piston 2!! of the piston rod IE is arranged to bealternately supplied to and relieved from the upper and lower cylinderends through pipes or ducts It and 45 which are alternatively connectedto iiuid pressure and returnpipes 4E and 41, and the fluid flow isarranged to be controlled by a suitable valve-mechanism provided in acasing 4B and controllable in accordance with the setting of a rotaryspindle or stem member 5l extending from the casing 48 and mountingcontrol arms 52 and 53 which extend generally horizontally andoppositely in fore-and-aft relation to the machine frame I2. A link 5Aextends from the arm 52 to a hinged connection with -an intermediatepoint of a setting lever 55 which extends forwardly along a side of theframe l2 from a pivot 5B at its rear end. A forward end portion 55 ofthe lever 52 is disposed within ready reachof an operator at the frontof the machine, and comprises a pedal in the present instance.

In its forward end, the arm 53 of the control member 5I is provided withan upright opening 53 through which an upright arm portion 5l ofjustably'- xed toV the piston rodi I 6 vjust above the die platemember 2I, as byv a suitable clamp58, and therod portion 51! is reciprocablyengagedlin an upright guideway provided -onthe frame IZ' at a pointbelow the range-of action of.A the valve control arm 53'. To effect itsfunctioning in a manner hereinafter brought out; a stop member 59isadjustably'mounted onthe upright shipper rod portion 57" and is arrangedto engage the top of the control arm53when the rod 5l issufficiently-lowered with respect to the positioned'saidfarm;

therod and piston arenormally heldfully raised by reason oftheconnection of theA cylinder botitomwith the pressure pipe tithrough thelcontrol valve and theduct-.. It will be noted that'the shipper rod arm51" is constantly operative to prevent a rotation ofthe piston rod,andthe die assembly I'I carried by it, whereby the cooperative alignmentof the upper and lower die assembliesvk is maintained.

Figure l indicates by the RomanV numerals'III andl V and VII- thepositionsv of the piston, 2.0 when the die assembly Il is in itsposition'of Fig:- ures 3 and 5 and 7 respectively. When a work.- piecesheet L of material to be cut has been-placed in appropriate positionupon the lower die assem'.- bly I8 while the movable die assembly Il isin its normal limiting raised position, a depression, of the pedal 52 isarranged to rotate the valvestem llt tovset the control valveforsupplying liquid from the supply pipe t6 to the top of the cylinderwhile connecting the lower cylinder portion with the return pipe Il? foreffecting the lowering of the die assembly Il toward the work-piece L tofinally engage the bottom faces ofthe presserfoot sections 32 and 3lwith theV work-piece, after which a continued lowering-of the piston rodunder the liquid pressure is operative to effect a cutting projection ofthe blade 22` beyond the presser feet and through and beyond theworkpiece.

As the die assembly I' approaches its limiting lowered position, thevalve control arm 53. is moved toward its normal position by reason ofthe engagement of the shipper rod block 59 therewith, and when the armreaches said position, the liquid connections for the top and bottom ofthelcylinder are automatically vrestored to their 1n1t1al conditions fora-repetition of the cutting application of the die assembly Il the nexttime the pedal 55 is depressed. The control-valvev functioning ispreferably such that the movement of 'the cutter assembly I1 to engageits presser foot parts 32 and 31 with a sheet L is relatively slow, thesubsequent working projection of the cutter beyond the presser foot isrelatively rapid to provide a snap severing of a blank from the sheet,and the final automatic return-stroke lifting o f the die assembly toits normal raised position 1s preferably relatively fast to minimize thetime required between operative cycles.

It will now be noted that the present die sets II-I are formed andcooperative to cut out a thumb-piece blank for a glove, and thatcorrespondingly constructed die sets may be provided for cutting out theother blanks for the glove.

since the provision of different blanks for use 1n the assemblies ofgloves and shoe uppers requires the use of different die sets I'I--I8for hide, the clearance between the normally separated die assemblies inthis machine must be suiicient to facilitate a manual positioning andrepositioning of the work sheet for cutting of a plurality of blanksfrom it.

From the foregoing description taken in connection with the accompanyingdrawings, the features and advantages of the presentV cutting die andits operative application will be readily understood by those skilled inthe art to which the invention appertains. While I have shown anddescribed a structure which I now consider to comprise a preferredembodiment of my invention, I desire to have it understood that theshowings are primarily illustrative, and that such changes anddevelopments may be made, when desired, as fall within the scope of thefollowing claims.

I claim:

1` In a machine for cutting blanks from workpieces of fibrous sheetmaterial, a support member carried by the machine for its axialreciprocation toward and from the workpiece and comprising a rodmounting a nut at an end thereof and providing a shoulder opposite saidnut in spaced facing relation thereto, and a cutting die comprising abase member intermediately aind slidably receiving the rod portionbetween the shoulder and nut and normally seated against the shoulder, acontinuous cutting blade extending iixedly from said base member, apresser-foot member having a forward face for engaging the opposed faceof a work-piece and normally having its forward face disposed beyond theblade edge, said presser-foot member being reciprocable within theblade-bounded space of the blade and slidably receiving the rod portionbetween the base member and the nut and being displaceable along saidrod portion toward the base member to a limiting position in which itcontacts the base member and being provided with a recess extendinginwardly from its forward face for constantly and freely receiving thenut, and means yieldingly urging a mutual separation of the base andpresser-foot members to a limit imposed by the shoulder and nut of therod.

2. In a machine for transversely cutting blanks from a Work-piece ofsheet material, a support member carried by the machine for its axialreciprocation toward and from the workpiece and comprising a rodproviding a radial stop at an end thereof and providing a shoulderopposite said stop in spaced facing relation thereto, and a cutting diecomprising a base member intermediately and slidably receiving the rodportion between the shoulder and stop and normally seated against theshoulder, a cutting blade extending xedly from said base member, apresserfoot member having a forward face for engaging the opposed faceof a work-piece and normally having its forward face disposed beyond theblade edge, said presser-foot memberrbeing reciprocable with respect tothe blade and slidably receiving the rod portion between the base memberand the stop at the rod end and being movable along said rod portiontoward the base member and being provided with a recess extendinginwardly from its forward face for constantly and freely receiving thestop, and means yieldingly urging a mutual separation of the base andpresser-foot members to a limit imposed by the shoulder and stop of therod.

JOSEPH E. MCCLEILAN.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date 22,873 Howard et al Feb. 8, 1859 334,554 Allstatter Jan. 19,1886 625,789 McBeth May 30, 1899 1,245,059 Strand Oct. 30, 19171,283,250 Mayle Oct. 29, 1918 1,303,680 Kent May 13, 1919 1,430,373Hennings Sept. 26, 1922 2,412,066 Shear Dec. 3, 1946

